he is the son of Broly but he lost his memory after a fight with Vegeta so he doesn't remember his real name. all he remembered was the letter J from his name and he also remembered his father but not his mother. he looked for his father until he found Goku who told him that his father was dead after being brought back by his mother,who was killed along with his father. so now he seeks revenge for the Z-fighters killing his parents. after killing thousands of innocent people in a blind rage,he met Goku again and Gohan who tried convincing him to change his was after they beat him but he just fled without saying a word. he lives in the wilderness but his mind has been conflicting with itself,debating whether or not to kill the ones that killed his parents or change his ways.